US7323153B2 - Reprocessing method by fluoride volatility process using fractional distillation - Google Patents
Reprocessing method by fluoride volatility process using fractional distillation Download PDFInfo
- Publication number
- US7323153B2 US7323153B2 US11/097,244 US9724405A US7323153B2 US 7323153 B2 US7323153 B2 US 7323153B2 US 9724405 A US9724405 A US 9724405A US 7323153 B2 US7323153 B2 US 7323153B2
- Authority
- US
- United States
- Prior art keywords
- puf
- fluoride
- gas
- fractional distillation
- fluorination
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G43/00—Compounds of uranium
- C01G43/04—Halides of uranium
- C01G43/06—Fluorides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G56/00—Compounds of transuranic elements
- C01G56/004—Compounds of plutonium
Definitions
- the present invention relates to a method of separating and purifying nuclear fuel substances using a difference in fluorination volatility behavior of uranium, plutonium and other elements in a spent oxide fuel to reprocess the spent oxide fuel.
- a fluoride volatility process is one of methods for dry reprocessing of a spent fuel, in which nuclear fuel substances such as uranium and plutonium and various kinds of nuclear fission products are separated and recovered using a difference in volatility behavior when they are fluorinated.
- Techniques for applying the fluoride volatility process to a reprocessing process have been developed in the U.S. and other various countries since 1950s. However, each of those techniques has problem in higher fluorination and purification of plutonium. None of these techniques has reached a practical phase, and there has been no progress since 1970s.
- uranium and plutonium are separated by two-stage fluorination using a fluidized bed furnace as a reactor with the temperature and fluorine concentration being changed. For example, in the first stage, uranium is fluorinated with an F 2 concentration of 20% at the operating temperature of 330° C., and in the second stage, plutonium is fluorinated with an F 2 concentration of 100% at the operating temperature of 330 to 550° C.
- plutonium is hard to be converted into plutonium hexafluoride (PuF 6 ) (the conversion ratio or conversion rate decreases) from the point of view of thermodynamics and reaction temperature because plutonium forms into PuF 4 of an intermediate fluoride in the first stage, and the fluorine concentration is so high that incomplete fluidization easily occurs.
- PuF 6 plutonium hexafluoride
- the flame furnace is a reactor operating under conditions of high temperature and high fluorine gas atmosphere.
- a reprocessing method by a fluoride volatility process using fractional distillation in which fluorine or a fluorine compound is subjected to a reaction with a spent oxide fuel in two stages to produce fluorides of uranium and plutonium, and recover uranium and plutonium as the fluorides using a difference in volatility behavior, the reprocessing method comprising the steps of:
- the first stage HF fluorination step is carried out preferably by supplying a hydrogen fluoride gas containing 10 to 30 vol % of hydrogen using a fluidized bed furnace operated in the temperature range of 350 to 430° C.
- the second stage F 2 fluorination step is carried out preferably by supplying a fluorine gas diluted to 20 to 40 vol % using a fluidized bed furnace operated in the temperature range of 500 to 750° C.
- the separation and volatilization step is carried out by using at least one cold trap, and the removal of the part of UF 6 is carried out by fractional distillation (gas-liquid separation) at the operating temperature and pressure controlled so that UF 6 is in a gas region and PuF 6 is in a liquid region in the phase diagrams of UF 6 and PuF 6 .
- the spent oxide fuel is subjected to a reaction with hydrogen fluoride mixed with hydrogen in the first stage, and the resultant fluorides are subjected to a reaction with a fluorine gas in the second stage, and thus PuF 4 hard to undergo a reaction into a higher fluoride is never produced as an intermediate fluoride, thus making it possible to improve the ratio and rate of conversion into PuF 6 and to reduce a consumption of expensive fluorine gas.
- the fluidized bed furnaces are used to carry out reactions under lenient conditions in both first and second stages, the furnaces are hard to be corroded or deteriorated.
- FIG. 1 is an explanatory diagram showing a basic process of a reprocessing method by a fluoride volatility process using fractional distillation according to the present invention
- FIG. 2 is a process flow showing one example of the reprocessing method by the fluoride volatility process using fractional distillation according to the present invention.
- FIG. 3 is a block diagram of an apparatus for carrying out the reprocessing method by the fluoride volatility process using fractional distillation according to the present invention.
- FIG. 1 is an explanatory view showing a basic process of a reprocessing method by a fluoride volatility process using fractional distillation according to the present invention.
- This is a reprocessing method in which fluorine or a fluorine compound is subjected to a reaction with a spent oxide fuel in two stages to produce fluorides of uranium and plutonium, and uranium and plutonium are recovered as UF 6 and UF 6 +PuF 6 using a difference in volatility behavior.
- the first stage is an HF-fluorination step, where HF fluorination of a spent oxide fuel containing UO 2 and PuO 2 is conducted in the reaction thereof with hydrogen fluoride mixed with hydrogen to produce UF 4 and PuF 3 .
- the HF-fluorination step is carried out by supplying a hydrogen fluoride gas (supply: 1.1 to 1.3 times the stoichiometric ratio, concentration: 60 to 90 vol %) containing 10 to 30 vol % of hydrogen using a fluidized bed furnace operated in the temperature range of 350 to 430° C.
- the second stage is an F 2 fluorination step, where F 2 fluorination of UF 4 and PuF 3 is conducted in the reaction thereof with a fluorine gas to produce UF 6 and PuF 6 .
- the F 2 fluorination step is carried out by supplying a fluorine gas (supply: 1.1 to 1.3 times the stoichiometric ratio) diluted to 20 to 40 vol % using a fluidized bed furnace operated in the temperature range of 500 to 750° C.
- Conversion of UF 4 by the fluorine gas is not particularly cumbersome because it has been already performed on a commercial scale, and conversion of PuF 3 into PuF 6 can be carried out at a low temperature (500 to 750° C.) easily, speedily and stably compared to the conversion of PuF 4 into PuF 6 .
- the above two-stage fluorination process according to the present invention has an advantage that PuF 6 can be produced without the intermediation of PuF 4 .
- the resulting UF 6 and PuF 6 are fractionally distillated using a difference in phase change thereof to remove a part of UF 6 as gas, and then the remaining UF 6 and PuF 6 are volatilized at the same time (separation and volatilization step).
- Cold traps are used in this step, and a part of UF 6 is removed by fractional distillation at the operating temperature and pressure controlled so that UF 6 is in a gas region and PuF 6 is in a liquid region in the well-known phase diagrams of UF 6 and PuF 6 .
- Conditions for the separation are set so that the pressure is about 83.6 kPa in the temperature range of 53 to 56.5° C. (about 85.01 kPa at 53.4 to 57° C.).
- UF 6 is vaporized and PuF 6 is liquefied, thus making it possible to separate them.
- the conditions are set in consideration of an operation on the negative pressure side, and therefore have a quite limited range, but if a separation operation is possible on the positive pressure side as well, an allowable range of pressure and temperature is wider. Then, the pressure is reduced to about 50 kPa, whereby the remaining UF 6 and PuF 6 are vaporized at the same time.
- the fluoride volatility process can be applied to recover uranium and plutonium as UF 6 and UF 6 +PuF 6 .
- This reprocessing process can be used for a light water reactor nuclear fuel cycle, FBR nuclear fuel cycle or the like. If the processing object is a spent metal fuel, the method of the present invention can be applied by oxidizing the metal fuel as preprocessing.
- FIG. 2 is a process flow showing one example of the reprocessing method by the fluoride volatility process using fractional distillation according to the present invention.
- This is an example of a process of reprocessing a spent oxide fuel.
- the spent oxide fuel as a raw material has been subjected to decladding processing, and its main constituent elements include U, Pu, O, Zr, Nb, Mo, Tc, Ru, Sb, Te, Cs, Np, Am and Cm, and uranium exists in a form of UO 2 and plutonium exits in a form of PuO 2 .
- These raw materials are fluorinated in two stages.
- a raw material spent oxide fuel
- an HF gas supply: 1.15 times the stoichiometric ratio, concentration: 70 vol %
- a fluidized bed furnace operating temperature: 400° C.
- an H 2 gas is also supplied, and the supply thereof is greater than 0.5 times the stoichiometric ratio to PuO 2 , and the concentration may be any of 5 to 100 vol %, but should be 30 vol % if the H 2 gas is supplied along with 70 vol % HF. Consequently, UF 4 and PuF 3 are produced.
- the intermediate fluorides produced in the first-stage HF fluorination are converted into the hexafluorides.
- the operating temperature of the fluidized bed furnace is set to 500 to 750° C., and the intermediate fluoride is subjected to a reaction with a fluorine gas to produce the hexafluorides of uranium and plutonium.
- the supplied fluorine gas is diluted with an N 2 gas to adjust the concentration of the fluorine gas to 20 to 40 vol % and the excess fluorine gas ratio to 1.15 times the stoichiometric ratio.
- uranium (UF 6 ) and plutonium (PuF 6 ) are volatilized along with many impurities, but ZrF 4 , CsF, PuF 4 , AmF 3 , CmF 3 and the like remain along with a bed material because of the low vapor pressure.
- Volatilized UF 6 and PuF 6 are condensed in cold traps.
- the operating temperature is ⁇ 70 to 0° C., and the working pressure is about 50 kPa.
- Many volatile substances are condensed under the conditions, but most of F 2 (boiling point: ⁇ 188.24° C.), HF (melting point: ⁇ 84.79° C., boiling point: 19.67° C.) and TeF 6 (boiling point: ⁇ 39.55° C.) each having a low melting or boiling point remains gaseous, and therefore solids and gases are separated from condensates.
- UF 6 is vaporized and PuF 6 is liquefied (for this purpose, the temperature and pressure are set so that UF 6 is in a gas region and PuF 6 is in a liquid region in the phase diagrams of UF 6 and PuF 6 ).
- UF 6 and PuF 6 can be fractionally distillated under the conditions. Volatilized amount of UF 6 can be optionally set by appropriately controlling the temperature and pressure in actual operations.
- a certain amount of UF 6 is volatilized, and then the pressure is reduced to about 50 kPa with the temperature of the cold traps unchanged, whereby UF 6 and PuF 6 can be vaporized at the same time.
- the temperature and pressure can be set in accordance with characteristics of the cold traps referring to the phase diagrams of UF 6 and PuF 6 .
- UF 6 produced by F 2 fluorination contains a very small amount of PuF 6 and volatile impurities. These impurities are made to pass through chemical traps filled with a substance having an action of chemically adsorbing the impurities, whereby the impurities can be removed to purify UF 6 . Chemical traps are installed in multiple stages as required.
- MgF 2 Chemical traps using MgF 2 as a filler are provided in the second stage.
- MgF 2 has an action of adsorbing NbF 6 , MoF 6 , TcF 6 , RuF 5 , SbF 5 and NpF 6 , and is used at the operating temperature of 120° C. here.
- NaF is known to adsorb UF 6 through the reaction of UF 6 +2NaF ⁇ Na 2 UF 8 at 25 to 250° C.
- Na 2 UF 8 decomposes into NaF and UF 6 again at 300 to 400° C., but NaF forms double salts with RuF 5 and NbF 6 .
- It has an action of adsorbing ZrF 4 , but most of ZrF 4 remains in the fluidized bed furnace as a nonvolatile substance along with the bed material, and only a very small amount thereof is removed by the NaF traps.
- a mixed gas of volatilized UF 6 and PuF 6 and UF 6 purified by the chemical traps are mixed together in a desired ratio using a gas mixer, and the plutonium enrichment is adjusted.
- a slightly negative pressure and a temperature of about 70 to 80° C. are adopted.
- UF 6 not used for adjustment of the plutonium enrichment of UF 6 purified by the chemical traps, or a mixed gas of UF 6 after adjustment of the plutonium enrichment and PuF 6 is condensed.
- the operating temperature is ⁇ 70 to 0° C., and the pressure is about 50 kPa.
- the temperature is increased to 70 to 80° C. with the pressure (50 kPa) unchanged, whereby the condensed UF 6 or mixture of UF 6 and PuF 6 is vaporized and provided for a reconversion process.
- vaporized simple UF 6 is filled in a cylinder for UF 6 , it can be used as a raw material for uranium enrichment, and this process can be used in a light water reactor fuel cycle.
- UF 6 can be liquefied and filled in the cylinder.
- FIG. 3 is a block diagram of an apparatus for carrying out the above reprocessing method by a fluoride volatility process using fractional distillation.
- a raw material (spent oxide fuel) in a raw material supply tank 10 is fed to an HF fluorination furnace (fluidized bed furnace) 12 , reacts with an HF+H 2 gas into an intermediate material, and is stored in an intermediate fluoride supply tank 14 .
- the intermediate fluoride in the intermediate fluoride supply tank 14 is fed to an F 2 fluorination furnace (fluidized bed furnace) 16 , and reacts with an F 2 gas into a hexafluoride.
- the obtained hexafluoride is introduced into first cold traps 18 , where UF 6 .PuF 6 is condensed, UF 6 /PuF 6 is separated, and UF6.PuF6 is volatilized.
- UF 6 is purified through LiF/UO 2 F 2 traps 20 , MgF 2 traps 22 and NaF traps 24 .
- UF 6 and UF 6 .PuF 6 are introduced into second cold traps 26 , where UF 6 is condensed and volatilized, and UF 6 .PuF 6 is condensed and volatilized, and they are provided for the reconversion process.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
Description
UO2(solid)+4HF═UF4(solid)+2H2O
PuO2(solid)+3HF+1/2 H2═PuF3(solid)+2H2O
<F2 Fluorination>
Claims (4)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004224444A JP4022608B2 (en) | 2004-07-30 | 2004-07-30 | Reprocessing method by fluoride volatilization method using fractional distillation |
JP2004-224444 | 2004-07-30 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20060057042A1 US20060057042A1 (en) | 2006-03-16 |
US7323153B2 true US7323153B2 (en) | 2008-01-29 |
Family
ID=36025688
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/097,244 Expired - Fee Related US7323153B2 (en) | 2004-07-30 | 2005-04-04 | Reprocessing method by fluoride volatility process using fractional distillation |
Country Status (2)
Country | Link |
---|---|
US (1) | US7323153B2 (en) |
JP (1) | JP4022608B2 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080265925A1 (en) * | 2004-09-13 | 2008-10-30 | Cascade Microtech, Inc. | Double sided probing structures |
US8116423B2 (en) | 2007-12-26 | 2012-02-14 | Thorium Power, Inc. | Nuclear reactor (alternatives), fuel assembly of seed-blanket subassemblies for nuclear reactor (alternatives), and fuel element for fuel assembly |
US8192704B1 (en) | 2011-02-25 | 2012-06-05 | The United States Of America As Represented By The Department Of Energy | Spent nuclear fuel recycling with plasma reduction and etching |
US20120156115A1 (en) * | 2008-07-29 | 2012-06-21 | Scheele Randall D | Systems and Methods for Treating Material |
US8654917B2 (en) | 2007-12-26 | 2014-02-18 | Thorium Power, Inc. | Nuclear reactor (alternatives), fuel assembly of seed-blanket subassemblies for nuclear reactor (alternatives), and fuel element for fuel assembly |
US9355747B2 (en) | 2008-12-25 | 2016-05-31 | Thorium Power, Inc. | Light-water reactor fuel assembly (alternatives), a light-water reactor, and a fuel element of fuel assembly |
US10037823B2 (en) | 2010-05-11 | 2018-07-31 | Thorium Power, Inc. | Fuel assembly |
US10170207B2 (en) | 2013-05-10 | 2019-01-01 | Thorium Power, Inc. | Fuel assembly |
US10192644B2 (en) | 2010-05-11 | 2019-01-29 | Lightbridge Corporation | Fuel assembly |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100759941B1 (en) | 2006-06-28 | 2007-09-18 | 한국원자력연구원 | Separation and recovery method of coating layer and internal particles from crushed TRISO fuel and apparatus thereof |
JP4801576B2 (en) * | 2006-12-19 | 2011-10-26 | 日立Geニュークリア・エナジー株式会社 | Spent nuclear fuel reprocessing method |
JP5124548B2 (en) * | 2009-09-04 | 2013-01-23 | 日立Geニュークリア・エナジー株式会社 | Powder sampling device |
JP5309054B2 (en) * | 2010-02-26 | 2013-10-09 | 日立Geニュークリア・エナジー株式会社 | Treatment method of waste fluoride adsorbent |
JP5409553B2 (en) * | 2010-08-26 | 2014-02-05 | 日立Geニュークリア・エナジー株式会社 | Nuclear fuel material fluorination apparatus, fluorination method and reprocessing method |
US9567237B2 (en) | 2012-11-16 | 2017-02-14 | Honeywell International Inc. | Separation and recovery of molybdenum values from uranium process distillate |
US20150064089A1 (en) * | 2013-08-29 | 2015-03-05 | Honeywell International Inc. | Fluidized bed reactors including conical gas distributors and related methods of fluorination |
US9511339B2 (en) * | 2013-08-30 | 2016-12-06 | Honeywell International Inc. | Series coupled fluidized bed reactor units including cyclonic plenum assemblies and related methods of hydrofluorination |
WO2018029787A1 (en) * | 2016-08-09 | 2018-02-15 | 株式会社日立製作所 | Method for separating zirconium and method for processing spent fuel |
CN109300555B (en) * | 2018-11-14 | 2021-01-08 | 中国核电工程有限公司 | Dry conversion device from uranium hexafluoride to uranium tetrafluoride |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3644104A (en) * | 1968-10-23 | 1972-02-22 | Georges Manevy | Process for processing canned irradiated ceramic fuel elements |
US3708568A (en) * | 1970-10-20 | 1973-01-02 | Atomic Energy Commission | Removal of plutonium from plutonium hexafluoride-uranium hexafluoride mixtures |
US3963564A (en) * | 1973-10-24 | 1976-06-15 | Commissariat A L'energie Atomique | Method for preventing tritium contamination of secondary salt and steam in a molten salt reactor |
US4710222A (en) * | 1987-02-13 | 1987-12-01 | The United States Of America As Represented By The United States Department Of Energy | Method for removal of plutonium impurity from americium oxides and fluorides |
US5076839A (en) * | 1988-02-17 | 1991-12-31 | Johnson Matthey Public Limited Company | Precious metal refining with fluorine gas |
US5118343A (en) * | 1991-04-23 | 1992-06-02 | The United States Of America As Represented By The United States Department Of Energy | Lithium metal reduction of plutonium oxide to produce plutonium metal |
RU2108295C1 (en) * | 1996-12-10 | 1998-04-10 | Всероссийский научно-исследовательский институт химической технологии | Method of preparing plutonium trifluoride from plutonium dioxide |
JP2001153991A (en) | 1999-11-25 | 2001-06-08 | Hitachi Ltd | Reprocessing of spent nuclear fuel |
US6442226B1 (en) * | 1996-06-06 | 2002-08-27 | The Regents Of The University Of California | Accelerator-driven transmutation of spent fuel elements |
-
2004
- 2004-07-30 JP JP2004224444A patent/JP4022608B2/en not_active Expired - Fee Related
-
2005
- 2005-04-04 US US11/097,244 patent/US7323153B2/en not_active Expired - Fee Related
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3644104A (en) * | 1968-10-23 | 1972-02-22 | Georges Manevy | Process for processing canned irradiated ceramic fuel elements |
US3708568A (en) * | 1970-10-20 | 1973-01-02 | Atomic Energy Commission | Removal of plutonium from plutonium hexafluoride-uranium hexafluoride mixtures |
US3963564A (en) * | 1973-10-24 | 1976-06-15 | Commissariat A L'energie Atomique | Method for preventing tritium contamination of secondary salt and steam in a molten salt reactor |
US4710222A (en) * | 1987-02-13 | 1987-12-01 | The United States Of America As Represented By The United States Department Of Energy | Method for removal of plutonium impurity from americium oxides and fluorides |
US5076839A (en) * | 1988-02-17 | 1991-12-31 | Johnson Matthey Public Limited Company | Precious metal refining with fluorine gas |
US5118343A (en) * | 1991-04-23 | 1992-06-02 | The United States Of America As Represented By The United States Department Of Energy | Lithium metal reduction of plutonium oxide to produce plutonium metal |
US6442226B1 (en) * | 1996-06-06 | 2002-08-27 | The Regents Of The University Of California | Accelerator-driven transmutation of spent fuel elements |
RU2108295C1 (en) * | 1996-12-10 | 1998-04-10 | Всероссийский научно-исследовательский институт химической технологии | Method of preparing plutonium trifluoride from plutonium dioxide |
JP2001153991A (en) | 1999-11-25 | 2001-06-08 | Hitachi Ltd | Reprocessing of spent nuclear fuel |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080265925A1 (en) * | 2004-09-13 | 2008-10-30 | Cascade Microtech, Inc. | Double sided probing structures |
US8116423B2 (en) | 2007-12-26 | 2012-02-14 | Thorium Power, Inc. | Nuclear reactor (alternatives), fuel assembly of seed-blanket subassemblies for nuclear reactor (alternatives), and fuel element for fuel assembly |
US8654917B2 (en) | 2007-12-26 | 2014-02-18 | Thorium Power, Inc. | Nuclear reactor (alternatives), fuel assembly of seed-blanket subassemblies for nuclear reactor (alternatives), and fuel element for fuel assembly |
US8867692B2 (en) * | 2008-07-29 | 2014-10-21 | Battelle Memorial Institute | Systems and methods for treating material |
US20120156115A1 (en) * | 2008-07-29 | 2012-06-21 | Scheele Randall D | Systems and Methods for Treating Material |
US9355747B2 (en) | 2008-12-25 | 2016-05-31 | Thorium Power, Inc. | Light-water reactor fuel assembly (alternatives), a light-water reactor, and a fuel element of fuel assembly |
US10037823B2 (en) | 2010-05-11 | 2018-07-31 | Thorium Power, Inc. | Fuel assembly |
US10192644B2 (en) | 2010-05-11 | 2019-01-29 | Lightbridge Corporation | Fuel assembly |
US10991473B2 (en) | 2010-05-11 | 2021-04-27 | Thorium Power, Inc. | Method of manufacturing a nuclear fuel assembly |
US11195629B2 (en) | 2010-05-11 | 2021-12-07 | Thorium Power, Inc. | Fuel assembly |
US11837371B2 (en) | 2010-05-11 | 2023-12-05 | Thorium Power, Inc. | Method of manufacturing a nuclear fuel assembly |
US11862353B2 (en) | 2010-05-11 | 2024-01-02 | Thorium Power, Inc. | Fuel assembly |
US8192704B1 (en) | 2011-02-25 | 2012-06-05 | The United States Of America As Represented By The Department Of Energy | Spent nuclear fuel recycling with plasma reduction and etching |
US10170207B2 (en) | 2013-05-10 | 2019-01-01 | Thorium Power, Inc. | Fuel assembly |
US11211174B2 (en) | 2013-05-10 | 2021-12-28 | Thorium Power, Inc. | Fuel assembly |
Also Published As
Publication number | Publication date |
---|---|
US20060057042A1 (en) | 2006-03-16 |
JP2006046957A (en) | 2006-02-16 |
JP4022608B2 (en) | 2007-12-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7323153B2 (en) | Reprocessing method by fluoride volatility process using fractional distillation | |
US7172741B2 (en) | Method for reprocessing spent nuclear fuel | |
Morel et al. | Uranium and fluorine cycles in the nuclear industry | |
US7208129B2 (en) | Reprocessing method by fluoride volatility process using solid-gas separation | |
CN110387473B (en) | Method for separating uranium and molybdenum by fluorination with nitrogen trifluoride as fluorinating agent | |
US3294493A (en) | Method of separating uranium and plutonium | |
JPH05271821A (en) | Method for recovering and purifying metal alloy consisting of uranium of extremely high content as base | |
US3178258A (en) | Separation of plutonium hexafluoride from uranium hexafluoride by selective sorption | |
CN113795894B (en) | Spent fuel dry post-treatment method based on plasma | |
Cathers | Uranium recovery for spent fuel by dissolution in fused salt and fluorination | |
JP3823593B2 (en) | Method for reprocessing spent nuclear fuel and method for reprocessing spent nuclear fuel | |
JP5043836B2 (en) | Method for recycling zirconium tetrafluoride to form zirconia | |
US3429669A (en) | Method of processing nuclear fuel by selective cif fluorination with separation of uf6 and puf4 | |
FR2742257A1 (en) | PROCESS FOR THE ENHANCEMENT, IN THE FORM OF NITRIC ACID, OF NITRATE IONS CONTAINED IN THE EFFLUENTS OF THE NUCLEAR INDUSTRY | |
JP2001153991A (en) | Reprocessing of spent nuclear fuel | |
JP2002071865A (en) | Method for producing mixed oxide fuel for nuclear reactor | |
JP5065163B2 (en) | Method for recycling uranium from spent nuclear fuel | |
JP2002255558A (en) | Method for converting fluoride into oxide | |
US4555318A (en) | Removal of fluoride impurities from UF6 gas | |
Watanabe et al. | Fluorination of niobium compounds with fluorine for fluoride volatility method | |
RU2112744C1 (en) | Method of processing high-concentration uranium | |
US3043653A (en) | Recovery of uranium from zirconiumuranium nuclear fuels | |
RU2292303C2 (en) | Method of preparing reduced-enrichment uranium hexafluoride from high-enrichment arms uranium | |
US3451790A (en) | Method of separating neptunium and uranium values | |
RU2106422C1 (en) | Method of treating uranium-based metal alloy |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: JAPAN NUCLEAR CYCLE DEVELOPMENT INSTITUTE, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:AMAMOTO, IPPEI;SATO, KOJI;REEL/FRAME:016448/0635 Effective date: 20050221 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
AS | Assignment |
Owner name: JAPAN ATOMIC ENERGY AGENCY, INDEPENDENT ADMINISTRA Free format text: CHANGE OF NAME;ASSIGNOR:JAPAN NUCLEAR CYCLE DEVELOPMENT INSTITUTE;REEL/FRAME:028023/0814 Effective date: 20051001 |
|
FEPP | Fee payment procedure |
Free format text: PAT HOLDER NO LONGER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: STOL); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20200129 |